In an application of the optical fiber communication technology, an electrical signal needs to be converted into an optical signal by using a transmitter optical device (for example, a laser), and the optical signal is then coupled to an optical fiber for transmission. In an actual application, the optical signal is generally coupled to the optical fiber by using a lens. When coupling is performed by using the lens, the fixing of the lens needs to be implemented online during the coupling, and the fixing may be implemented by adhering with adhesive.